Abstract
Drugs are metabolized in liver and/or target organs mainly. However the metabolizing enzyme activity is variable in individuals because of genetical deviations, aging, environmental factors and so on. Monitoring of drug levels in biological fluids is, therefore, neaded to avoid side effects and hyper responses. Recently, elegant methods, immunoassay based upon the antigen-antibody reaction and high-performance liquid chromatography (HPLC), have been introduced into the clinical field. In this review we describe the basics and applications for drug level monitoring of these methods. Gas chromatography is also discussed briefly.
